Inhalers or inhalation devices that deliver their content in the forms of liquid mists and powder in aerosol forms, are in common use today. However, these inhalers typically employed propellants, whose effectiveness is pressure, and thus, altitude and atmospherically dependent. Additionally, propellants such as chlorofluorocarbon propellants are banned by treaties, as they are harmful to the environment.
As a result, dry powder inhalers or inhalation devices were developed. However, these dry powder inhalers were of limited use, especially when delivery of medication to the deep lung was desired.
These dry powder inhalers exhibited drawbacks in that their design resulted in particles moving too fast or agglomerating. When particles traveled too fast, they typically struck the back of the throat, where they were swallowed, without ever reaching the lungs. Similarly, particles that agglomerated were too heavy, and typically fell out of the inhaled breath stream in the mouth or oral cavity, where they were swallowed without ever reaching the lungs. Accordingly, the powder, if any, that reached the lungs was typically in amounts ineffective for proper treatment.
Moreover, these conventional inhalers are relatively large. As a result of this large size, their portability, in pockets and other compartments is limited, and to a greater extent, the space required for their use is large. For example, the space required for use of these conventional inhalers would make them difficult, if not impossible to use under a gas mask or the like, as the airspace therein is extremely limited. Coupled with the amount of space taken up in pockets, first aid kits, etc., many of these conventional inhalers are not suited for battlefield and other emergency uses.